The hydrosilylation in which a compound having vinyl group and a compound having hydrogen atom bonded to the silicon atom are reacted in the presence of a platinum catalyst for addition of both compounds is a technology well known in the art for synthesis and modification of an organosilane or an organopolysiloxane and silylation of an organic compound or an organic high molecular weight molecule.
Production method of a compound having a hydrogencarbonoxysilyl group such as an alkoxysilyl group may be divided into the following two categories.
<First Method>
A method wherein an aliphatic unsaturated organic compound is hydrosilylated by using a hydrogenchlorosilane compound, and then converting the chlorosilyl group into an alkoxysilyl group by using an alcohol.
<Second Method>
A method wherein an aliphatic unsaturated organic compound is hydrosilylated by using a hydrogenalkoxysilane compound.
Of these two methods, the procedure of the second method is more convenient, and the second method is also superior in the productivity in view of the smaller amount of ionic impurities and waste generated in the alkoxylation. However, the hydrogenalkoxysilane compound is inferior to the hydrogenchlorosilane compound in the hydrosilylation activity, and it was also a material with low selectivity of the addition site since migration of the double bond in the unsaturated organic compound was promoted.
As a method for improving reactivity of the hydrosilylation and controlling the addition site by suppressing the migration of the double bond in a system using a hydrogenalkoxysilane, JP-A 2000-143679 and JP-A H11-180986 propose a method for hydrosilylating a hydrogenalkoxysilane and an aliphatic unsaturated organic compound or a vinyl-substituted aromatic compound by using a platinum catalyst in the presence of a carboxylic acid compound. However, in these methods, sufficient control of the addition selectivity was not realized, and regulation of the generation of the side product from the carboxylic acid by transesterification as well as adjustment of an amount added was difficult. In addition, hydrosilylation reactivity with the unsaturated organic compound containing tertiary amine atom, for example, allyl isocyanate or triallyl isocyanurate was still insufficient in these technologies.
As a matter of course, improvement of the hydrosilylation reactivity leads to the improvement of the reaction yield, and hence, improvement of the production efficiency. An organosilicon compound having its terminal carbon atom hydrosilylated exhibits higher performance than its isomers which has been silylated at a position other than its terminal when it is used as a coupling agent or a modifying agent. In the case of an organopolysiloxane, various physical properties including heat resistance are superior compared to the isomers. Accordingly, a hydrosilylation method capable of producing an organosilicon compound having a hydrosilylated terminal at a high yield and high selectivity has been awaited.